How to create a flat head screwdriver?
Shift+A Add Circle (Press F6 and set the vertices 6)



In the Edit Mode Press F key to fill the faces and extruded with the E key.



Now Add Plane and rotate little to get some shape and angle of the pointer of the screwdriver



In Edit mode of plane extrude the plane with the E key to some thickness to plane.



Now in Edit mode of the plane. Press Alt+D Duplicate the plane in X axis and move forward and press Ctrl+M to mirror the plane. Press Ctrl+N to flip normals.

Come out of the Edit Mode Select the Plane and Shift select the Extrude circle and Press Spacebar and type align object and press F6 and select x axis



Come out from Edit mode of Plane and select the extruded circle. Add Boolean Modifier. Select the Operation to Difference and object to plane. Apply the Modifier and delete the plane. Now you can get the shape of the pointer of screwdriver.